Abstract: A steer-by-wire system for a vehicle that provides synchronization capability to an actuator of a steerable device and an actuator of a steering input device includes a steering input device actuator operably connected to the steering input device of the vehicle and a steerable device actuator operably connected to the steerable device of the vehicle. The steerable device actuator is disposed in electronic communication with the steering input device actuator. The electronic communication is defined such that synchronous positioning of the steering input device actuator and the steerable device actuator can be effectuated by the system upon startup of the vehicle. A method of using the system includes initiating operation of the system by turning on an ignition switch of the vehicle and evaluating an initial condition of the vehicle. The initial condition is associated to the positions of the steering input device actuator and the steerable device actuator.

Abstract: A steer-by-wire system for a vehicle that provides synchronization capability to an actuator of a steerable device and an actuator of a steering input device includes a steering input device actuator operably connected to the steering input device of the vehicle and a steerable device actuator operably connected to the steerable device of the vehicle. The steerable device actuator is disposed in electronic communication with the steering input device actuator. The electronic communication is defined such that synchronous positioning of the steering input device actuator and the steerable device actuator can be effectuated by the system upon startup of the vehicle. A method of using the system includes initiating operation of the system by turning on an ignition switch of the vehicle and evaluating an initial condition of the vehicle. The initial condition is associated to the positions of the steering input device actuator and the steerable device actuator.

Abstract: A method for passively starting an electric power steering (“EPS”) system includes disabling assist torque upon power-up, detecting an index pulse upon a movement of a steering column across one of a plurality of reference positions, enabling assist torque for the EPS system upon detecting the index pulse, receiving a variable input torque command indicative of an external steering input, and ramping a variable assist motor torque towards the variable input torque command after enabling assist torque for the EPS system until the variable assist torque is substantially equal to the variable input torque command; wherein an EPS system apparatus includes a steering wheel for receiving operator inputs coupled to a steering column, a motor coupled to the steering column for applying torque assist to the column, an encoder coupled to the motor for determining the angular displacement of the steering column where the encoder comprises at least one track and a set of sensors for sensing the at least one t

Abstract: A method for passively starting an electric power steering (“EPS”) system includes disabling assist torque upon power-up, detecting an index pulse upon a movement of a steering column across one of a plurality of reference positions, enabling assist torque for the EPS system upon detecting the index pulse, receiving a variable input torque command indicative of an external steering input, and ramping a variable assist motor torque towards the variable input torque command after enabling assist torque for the EPS system until the variable assist torque is substantially equal to the variable input torque command; wherein an EPS system apparatus includes a steering wheel for receiving operator inputs coupled to a steering column, a motor coupled to the steering column for applying torque assist to the column, an encoder coupled to the motor for determining the angular displacement of the steering column where the encoder comprises at least one track and a set of sensors for sensing the at least one t

Abstract: A rotary encoder capable of detecting angular rotation of a rotating shaft, and identifying its neutral position without the need for multiple encoder wheels. A magnetoresistive sensor is positioned adjacent the periphery of a single multipole magnet ring attached to a steering wheel shaft. The magnet ring comprises alternating N-pole and S-pole magnetic regions along its periphery, the surface of one of the regions containing a demagnetized portion. The sensor produces a sinusoidal signal as the shaft is rotated, responsive to the passage of the magnetic regions, with a period equal to the passage of two successive magnetic regions adjacent the sensor. The angular position of the shaft which aligns the demagnetized portion adjacent the sensor corresponds to the shaft's neutral position. Aligning of the demagnetized portion adjacent the sensor causes a voltage irregularity within the sensor's otherwise sinusoidal output signal, which is detected by a signal processing circuit.

Abstract: A power steering unit has an electromagnetic mechanism controlled by a computer-based controller for varying the steering effort in accordance with vehicle speed. The same controller is used to adjust the steering effort in accordance with a calibration value to obtain steering effort uniformity. The calibration value is obtained by applying a force to a vehicle wheel and measuring the resulting torque on the steering wheel (or vice versa) and comparing the resulting force to a standard. Any deviation from the standard is stored in the controller as a correction factor. Alternatively, the characteristics of the steering gear and the power steering pump are measured and encoded on the unit when manufactured and the encoded values are read after assembly in a vehicle and used to calculate the correction factor which is then stored in the controller.

Abstract: A hydraulic power steering system having conventional relatively rotatable spool and valve body elements for flow regulation, and an integral electromagnetic mechanism which effectively varies the centering force between the spool and valve body to adjust the level of steering assist provided for a given operator steering input. The electromagnetic mechanism includes a rotary magnetic circuit and a stationary magnetic circuit. The rotary magnetic circuit comprises a pair of radially displaced magnetic pole pieces which rotate with the input shaft and a permanent magnet ring element which is disposed between the pole pieces and which rotates with the pinion shaft. The stationary magnetic circuit includes an annular exciting coil disposed in proximity to the rotary magnetic circuit. The exciting coil is energized so as to vary the valve body/spool centering force, and hence the driver steering effort, with vehicle speed.

Abstract: A hydraulically assisted power steering system subject to variance in steering effort due to temperature change is compensated to give consistent response at all temperatures. A hydraulic control valve is coupled to an electromagnetic device which controls the steering effort as a function of energization current. The current is adjusted in accordance with temperature to compensate for temperature changes. A microcomputer controller stores empirical data relating to the effect of temperature on steering effort and calculates the current adjustment necessary for any measured system temperature. In one embodiment, the temperature is not measured directly but is derived from the deviation of energization current from the theoretical desired current, which deviation is a function of temperature. The effect of voltage variations is also compensated for.

Abstract: A hydraulic power steering system having conventional relatively rotatable spool and valve body elements for flow regulation, a mechanically resilient element for generating a mechanical centering force in relation to the relative rotation of the spool and valve body to a centered condition, and an integral electromagnetic mechanism which variably assists the mechanical centering force to adjust the level of operator steering input required to produce a given level of power assist. The electromagnetic mechanism comprises an energized coil and a pair of flux conducting elements supported for rotation with the spool and valve body, respectively.

Abstract: An actuator has a permanent magnet ring with a plurality of radially magnetized poles rotatably positioned between a pair of toothed pole pieces with interdigitated teeth, an electromagnetic coil and pole elements coupling the coil flux to the pole pieces. The pole pieces may themselves be rotatable or stationary. The permanent magnet circuit attempts to move the magnet ring to a first position relative to the pole pieces, and the electromagnetic circuit, depending on the direction of current in the coil, torques the magnet in one direction or another toward stable positions on either side of the first position. The device is used as a two or three position actuator or as an actuator operating against an external force and seeking a position as a function of current.

Abstract: A homopolar actuator has a permanent magnet disk element rotatably positioned between a pair of toothed pole pieces with mutually offset teeth, an electromagnetic coil and pole elements coupling the coil flux to the pole pieces. The pole pieces may themselves be rotatable or stationary. The permanent magnet circuit attempts to center the disk element relative to the pole pieces, and the electromagnetic circuit, depending on the direction of current in the coil, either reinforces the centering action or overcomes the centering force to displace the elements from center position. The device is used as a two or three position actuator or as an actuator or magnetic spring operating against an external force and seeking a position as a function of current.

Abstract: A hydraulic power steering system having conventional relatively rotatable spool and valve body elements for flow regulation, a mechanically resilient element for generating a mechanical centering force in relation to the relative rotation of the spool and valve body which tends to restore the spool and valve body to a centered condition, and an integral electromagnetic mechanism which variably opposes the mechanical centering force to adjust the level of operator steering input required to produce a given level of power assist. The electromagnetic mechanism comprises an energized coil and a pair of flux conducting elements supported for rotation with the spool and valve body, respectively. The flux conducting elements have interleaved teeth which are magnetically coupled to the coil to define a magnetic circuit having an inter-tooth working air gap which varies with the relative rotation of the spool and valve body.

Abstract: A hydraulic power steering system having conventional relatively rotatable spool and valve body elements for flow regulation, and an integral electromagnetic mechanism which effectively varies the centering force between the spool and valve body to adjust the level of steering assist provided for a given operator steering input. The electromagnetic mechanism comprises a rotary multipole permanent magnet supported for rotation with one of the spool and valve body elements, a rotary flux conducting element supported for rotation with the other of the spool and valve body elements, and a stationary exciting coil magnetically coupled thereto. The exciting coil is energized so as to produce a variable centering force between the spool and valve body with vehicle speed, which produces a corresponding variation in the driver steering effort.

Abstract: A hydraulic power steering system having conventional relatively rotatable spool and valve body elements for flow regulation, and an integral electromagnetic mechanism which effectively varies the centering force between the spool and valve body to adjust the level of steering assist provided for a given operator steering input. The electromagnetic mechanism includes a rotary magnetic circuit and a stationary magnetic circuit. The rotary magnetic circuit comprises a pair of axially displaced magnetic pole pieces which rotate with the pinion shaft and a permanent magnet disk element which is disposed between the pole pieces and which rotates with the input shaft. The stationary magnetic circuit includes an annular exciting coil disposed about the rotary magnetic circuit and ferromagnetic pole elements adjacent each of the rotary pole pieces. The exciting coil is energized so as to vary the valve body/spool centering force, and hence the driver steering effort, with vehicle speed.

Abstract: A thermistor circuit for sensing the temperature of an intermittent duty wound field motor is connected between the field and armature windings of the motor. When the field and armature winding currents are substantially zero (off duty), the resistance of the thermistor circuit is sampled by the motor controller, using the armature and field winding conductors.

Abstract: To couple light signals between two relatively rotating parts, two rings of transparent material, each mounted on one of the parts, are provided on a common axis and have a slight spacing between their rings which is filled with an index matching fluid. Recesses in each ring are provided to receive light emitters or detectors, respectively. Each recess defines a curved wall serving as a light collection or focusing lens which serves as a window into or out of a ring. The assembly is completed by a pair of coaxial spacers or retainers each of which are mounted on one of the relatively rotating parts and also secured to one of the transparent rings. Light coupled into one of the rings through a window is transmitted by the index matching fluid to the other ring and it is emitted from a window of that ring.